Slugs
I loved slugs when I was a kid & I still love them now!
All slugs produce mucus but some species more than others, some seem to produce almost none at all unless picked up, in which case they will release extra to deter predators.
As with any animal, if you handle them, wash your hands thoroughly afterwards.
Slugs love to explore & are fascinating to watch as long as conditions are kept only slightly damp - slugs don't like to live in a mud pit.
All of our slugs have a section of thick plastic (cut from a an old compost bag) folded in half under damp moss - they love to hide in the folds.